The relative roles of the kidney and liver in the conjugation and excretion of compounds will be investigated, specifically the quantitation of biliary and urinary metabolites and conjugation and excretion patterns in: a) subjects injected into the renal artery with a carbon-14 labeled compound and, simultaneously, peripherally with a tritium labeled compound to gain insight into the mechanism by which the kidney metabolizes, conjugates and excretes or retains a compound, b) animals injected with labeled estrogens, c) animals (baboons) and humans injected with radioactive diethlstilbestrol, labeled with carbon-14, and d) normal subjects injected with radioactive progesterone. Two novel and highly sophisticated procedures developed with the aid of Grant AM-11754 will be used in this work. First is the fractionation of biological fluids using CCD without prior treatment of any kind, and analysis, by computer of the data (amount of radioactivity per tube and tube number) to obtain the number, partition coefficient and percentage of solutes in CCD for each compound. This assures both minimal artifact formation and no loss of radioactivity. The combination of mathematical approach and CCD, therefore, provides a truer picture of the excretion pattern than has been hitherto possible. Second, identification of conjugates without the necessity of prior hydrolysis can be achieved by co-distribution of the compound with an appropriate standard, labeled with a different isotope or unlabeled. The degree of overlap of the two resulting curves is statistically calculated and verdicts of match or no match are arrived at taking into consideration the possible presence of an isotope effect. We shall also use DEAE Sephadex columns for fractionation, a technique which we have found complementary to CCD. BIBLIOGRAPHIC REFERENCES: Ishihara, M., Osawa, Y., Kirdani, R. and Sandberg, A.A. Metabolic Fate of Ethynodiol Diacetate in the Baboon. Steroids 25: 829-847 (1975). Honjo, H., Ishihara, M., Kirdani, R. Y. and Sandberg, A.A. Renal Conjugation and Metabolism of Estradiol-17 beta and Estrone. The Endocrine Society, 57th Annual Meeting, 1975.